Last season, Ms Young was concerned penguins were only using one of the three entry points to Boulder Beach's breeding area as older, established breeders were blocking access paths.
Then, the mass mortality event reduced adult penguin numbers at many breeding sites including Sandfly Bay. Its adult population was halved.
So, Ms Young decided to try the decoys on Otago Peninsula to attract new penguins to those colonies.
She enlisted fellow staff to cut out a penguin shape from leftover plywood and paint it in a penguin's likeness, copying "Jeff" a damaged display penguin.
With the help of Dulux, a paint sponsor of Doc's, they were able to get paint to match the penguin, she said. Volunteer Gillian Cranfield was enlisted to paint their faces.
The initial decoys, which were attached to stakes, had been in place for a few months and had proven very successful, judging by the reaction of humans and penguins, Ms Young said.
"As a conservation tool they are perfect. They definitely seem to be working by the amount of poo all around them."
At Sandfly Bay, volunteers had recorded 22 penguins coming on to the beach compared with about 16 penguins which had nested there in the past.
Volunteers would help construct 40 more decoys late this month.